Many highway vehicles are equipped with citizen band (CB) or two way radios. Such radios enable a driver of a vehicle to select one of the channels to broadcast a call for assistance. At any one time there is a strong likelihood that someone will be monitoring the channel upon which the call for assistance has been broadcast and will notify authorities.
However, problems are encountered when one wishes to summon assistance from, or communicate with, a particular vehicle. In order to communicate, one must know which of a plurality of possible channels the driver of the vehicle is monitoring. This requires a person attempting to communicate to broadcast channel by channel until the correct channel is found. If one does not happen upon the correct channel in a timely fashion, the opportunity for communication is lost.